Flight Planning and Conduct of the X-24B Research Aircraft Flight Test Program

This report presents an overall summary of the conduct and results of the X-24B research aircraft flight test program. The program objective to obtain flight test verification of this efficient hypersonic aerodynamic shape was accomplished in 36 flights over a 26 month time period. The X-24B was air launched from a NB-52B, accelerated to test conditions by rocket power and glided to an unpowered landing. Research data and flight verification were obtained to a maximum Mach number of 1.76. The handling qualities at subsonic speeds and during landing were excellent. Accuracy landing tests demonstrated touchdown accuracy within or - 500 feet providing confidence to allow the first landing of a low LD aircraft on a conventional concrete runway. The longitudinal stability was less than predicted by small scale wind tunnel tests. Directional stability was found to be significantly less than predicted above 1. 3 Mach number resulting in a marked loss of usable LD capability. Rocket engine exhaust degraded directional stability at transonic and supersonic conditions. Subsonic gliding performance was close to predictions.